(1/253) Lymphangiosarcomas in cats: a retrospective study of 12 cases.
Clinical, macroscopic, and histologic features of 12 lymphangiosarcomas in cats are described. Nine tumors were located in the subcutaneous tissue at the caudoventral abdominal wall (eight cats) or in the neck (one cat). The remaining three cats had lymphangiosarcomas around the cranial mesenteric artery (two cats) or precardial in the mediastinum (one cat). Macroscopically, the tumors were noncircumscribed, white, edematous, and intermixed with fat tissue. Histologic features varied from cleft-forming and cavernous growth to papilliform and solid patterns. Follow-up data were available for seven cats with subcutaneous lymphangiosarcomas. All these cats died or were euthanatized within 6 months after surgery because of poor wound healing, local recurrence, or distant metastases. The cats with abdominal or thoracic masses were either euthanatized at surgery or within 6 months after the first surgery because of recurrent chylothorax, chyloperitoneum, or distant metastases. (+info)
(2/253) Intramuscular desmoid tumor (musculoaponeurotic fibromatosis) in two horses.
Intramuscular desmoid tumors (musculoaponeurotic fibromatosis) were discovered in two young adult horses. The tumor in one horse was in the lateral cervical musculature, and that in the second horse occurred in the pectoral musculature. Histopathologic features were similar in both horses and included proliferation of fibroblasts and cells expressing muscle actin (myofibroblasts), with extensive dissecting fibrosis within muscle. These features are similar to those of desmoid tumors in humans, particularly those also known as musculoaponeurotic fibromatosis. Dissection of these lesions revealed a single central (horse No. 1) or multiple central (horse No. 2) fluid-filled cavities with associated sterile inflammation. The presence of these cavities supports the hypothesis that equine desmoid tumors are traumatic in origin, possibly occurring at sites of injections or bursal rupture. Surgical excision of the tumor in horse No. 1 was apparently curative, but the extent of the tumor in horse No. 2 precluded surgical excision. (+info)
(3/253) Biosynthesis of heparin/heparan sulfate: kinetic studies of the glucuronyl C5-epimerase with N-sulfated derivatives of the Escherichia coli K5 capsular polysaccharide as substrates.
The D-glucuronyl C5-epimerase involved in the biosynthesis of heparin and heparan sulfate was investigated with focus on its substrate specificity, its kinetic properties, and a comparison of epimerase preparations from the Furth mastocytoma and bovine liver, which synthesize heparin and heparan sulfate, respectively. New substrates for the epimerase were prepared from the capsular polysaccharide of Escherichia coli K5, which had been labeled at C5 of its D-glucuronic and N-acetyl-D-glucosamine moieties by growing the bacteria in the presence of D-[5-(3)H]glucose. Following complete or partial ( approximately 50%) N-deacetylation of the polysaccharide by hydrazinolysis, the free amino groups were sulfated by treatment with trimethylamine.SO(3)complex, which yielded products that were recognized as substrates by the epimerase and released tritium from C5 of the D-glucuronyl residues upon incubation with the enzyme. Comparison of the kinetic properties of the two substrates showed that the fully N-sulfated derivative was the best substrate in terms of its K(m)value, which was significantly lower than that of its partially N-acetylated counterpart. The V(max)values for the E.coli polysaccharide derivatives were essentially the same but were both lower than that of the O-desulfated [(3)H]heparin used in our previous studies. Surprisingly, the apparent K(m)values for all three substrates increased with increasing enzyme concentration. The reason for this phenomenon is not entirely clear at present. Partially purified C5-epimerase preparations from the Furth mastocytoma and bovine liver, respectively, behaved similarly in terms of their reactivity towards the various substrates, but the variation in apparent K(m)values with enzyme concentration precluded a detailed comparison of their kinetic properties. (+info)
(4/253) Tenosynovial giant cell tumor of finger, localized type: a case report.
The authors report a typical case of tenosynovial giant cell tumor of the right middle finger of a 31-year-old man. Histologically, this tumor is characterized by a discrete proliferation of rounded synovial-like cells accompanied by a variable number of multinucleated giant cells, inflammatory cells, and xanthoma cells. Clinicopathologically, this tumor is a benign lesion that nonetheless possesses a capacity for local recurrence. Local excision with a small cuff of normal tissue is the treatment of choice in this tumor. (+info)
(5/253) Cytoplasmic domain mutants of beta1 integrin, expressed in beta 1-knockout lymphoma cells, have distinct effects on adhesion, invasion and metastasis.
Structural requirements for beta 1 integrin cytoplasmic domain functions in adhesion, migration and signaling have been studied mainly for fibroblasts in vitro. The relevance for beta 1-dependent in vivo migration of lymphoid cells has not been assessed. To study this, we transfected beta 1 mutants into beta 1-deficient double knockout (DKO) ESb lymphoma cells, and tested the capacity of the cells to metastasize to liver and spleen. This was compared to alpha 4 beta 1-dependent invasion into cell monolayers in vitro and Mn2+-induced adhesion to fibronectin. Deletion of the five C-terminal residues or mutation of both threonines T788 and T789 to alanines blocked invasion and metastasis and greatly reduced adhesion, in line with known in vitro effects. However, mutations of the NPXY motif tyrosines had unexpected consequences. A Y783F mutation had no effect at all, but a Y783,795F double mutation strongly reduced Mn2+-induced adhesion, whereas it had limited effects on invasion and metastasis. Furthermore, cells expressing a beta 1 beta 2 chimeric subunit, which contains phenylalanines in the NPXY/F motifs, adhered poorly but invasion and metastasis was fully restored to the same levels as for cells expressing wild-type beta 1. We conclude that part of the functions of the beta 1 cytoplasmic domain that are required for adhesion are not essential for beta 1-dependent invasion and metastasis. (+info)
(6/253) Extra-abdominal desmoid tumor of the hand: a case report and review of the literature.
Extra-abdominal desmoid tumor of the hand is rare and only 10 cases have been described in the literature. We present a 14-year-old boy with a recurrent extra-abdominal desmoid tumor in the dorsal site of the right hand. MR image demonstrated the tumor in the third dorsal interosseous muscle, and adhered to the radial side of the forth metacarpal bone. The lesion revealed iso-signal intensity on T1-weighted images and high intensity on T2. We performed a marginal excision. Histological examination of the tumor showed proliferation of the fibroblastic cells with abundant collagen bundles. He developed local recurrence for the third time. The size of the third recurrent tumor has not been changed for 2 years and 3 months. Therefore, we have not performed any additional surgery. Since extensive resection markedly diminishes the function of the hand, we consider that a marginal surgical margin is acceptable for the quality of daily life of patients with a desmoid tumor of the hand. (+info)
(7/253) Irradiation of a primary tumor, unlike surgical removal, enhances angiogenesis suppression at a distal site: potential role of host-tumor interaction.
Changes in distal angiogenesis in response to irradiation of primary tumors are not known. To this end, PC-3, a human prostate carcinoma, and FSA-II, a murine fibrosarcoma, were grown in the gastrocnemius muscles of male nude mice. Distal angiogenesis was measured in gel containing human recombinant basic fibroblast growth factor placed in the cranial windows of these mice. PC-3-bearing mice showed inhibition of distal angiogenesis, as compared with non-tumor-bearing controls. Surgical removal of tumors tended to accelerate distal angiogenesis; in comparison, after irradiation of the PC-3 primary tumor, rates of angiogenesis in the cranial window were retarded. Irradiation of the non-tumor-bearing leg or of non-tumor-bearing animals showed no measurable effect on rate of growth of vessels in the cranial window. Similar results were found with the FSA-II tumors, with slowed distal angiogenesis in tumor-bearing animals and further suppression in animals with irradiated tumors. These results demonstrate that the effect of irradiation of a primary tumor on angiogenesis at a distal site may differ from the effect of surgical removal of the primary tumor. Unlike surgery, irradiation of a tumor may enhance angiogenic suppression at a distal site, and this difference may involve host-tumor interaction. (+info)
(8/253) h-Caldesmon as a specific marker for smooth muscle tumors. Comparison with other smooth muscle markers in bone tumors.
Caldesmon is a protein widely distributed in smooth and non-smooth muscle cells and is thought to regulate cellular contraction. Its isoform, high-molecular-weight caldesmon (h-CD), was demonstrated to be specific for smooth muscle cells and smooth muscle tumors of the soft tissue and to never be expressed in myofibroblasts. We performed an immunohistochemical study to examine h-CD expression in the following bone tumors: conventional and non-conventional osteosarcoma, 13; malignant fibrous histiocytoma of bone, 5; giant cell tumors of bone, 5; chondroblastoma, 3; metastatic leiomyosarcoma, 2; and rhabdomyosarcoma, 1. Frequent immunoreactivity for muscle actin (alpha-smooth muscle actin or muscle-specific actin) was seen in 11 of 13 osteosarcomas and all other tumors, whereas h-CD was expressed intensely only in 2 leiomyosarcomas. h-CD is considered a specific and useful marker to distinguish smooth muscle tumor from bone tumors with myoid differentiation. (+info)